Intracutaneous injector with capillary gap



Jan. 22, 1963 M. s. COOPER ETAL INTRACUTANEOUS INJECTOR wrm CAPILLARY GAP Filed May 17, 1960 Alia/Alf United States Patent Ofifice 3,074,403 Patented Jan. 22, 1963 3,074,403 INTRACUTANEOUS INJECTOR WITH CAPILLARY GAP Murray Sam Cooper, Dumont, N.J., Arthur Sinclair Taylor, Spring Valley, N.Y., and Virgil Alan Place, Saddle River, N.J., assignors to American Cyanamid Company, New York, N.Y., a corporation of Maine Filed May 17, 1960, Ser. No. 29,627 3 Claims. (Cl. 128-253) This invention relates to an intracutaneous injector for the administration of biologically-active preparations having dual points, which are closely adjacent, and having gaps between them which, by capillary action, serves to retain liquids and therefore give more effective treatment.

Certain biological agents, which are either living organisms or derived from living organisms, are used in either a substantially dry or liquid form for the diagnosis, prevention or treatment of diseases. Certain of these, including viral and bacterial vaccines, viral and bacterial antigens, antibacterial and antitoxic antiserums, pollen extracts, and protein extracts, have been administered through the skin by scarification, subcutaneous injection and intradermal injection.

For the rapid treatment of large numbers of subjects, there is a demand for an intracutaneous injector which is so inexpensive that it can be used but once and discarded, and which gives quick and accurate dosage employing the biologics in either dry or liquid form. Among the present methods of treatment, as for example in vaccination for smallpox, a drop of the desired biologically-active material is placed on the cleansed skin of the subject, and a needle point is repeatedly pressed through the active liquid and into the skin carrying with it the vaccine. Such a method of administration is comparatively slow and requires skill in the use of the needle.

Various multiple-point devices have been developed to give a multiplicity of abrasions or small cuts in a single operation. Some of these have no method of depth control other than the skill of the user. Others, such as shown in United States Patent No. 2,893,392, A. R. Wagner and M. S. Cooper, Article of Manufacture for Intracutaneous Injections, have a plurality of sharp points or prongs protruding from a plate which gives control over the depth of penetration of the prongs and which is designed to have the biologic carried into the skin of the subject by the action of the prongs.

It has now been found that by having two prongs closely adjacent, with a narrow slot or gap between them, the liquid is drawn into the gap by capillary action and retained in the gap. The two prongs cut a more uniform wound in the skin and, therefore, give a reliable, uniform dosage. With biologics which are dried before use, the biologic may be placed on the twin prongs in liquid form and then dried. With biologics which are to be used in liquid form, the liquid is retained by capilliary action in the gap. It is found that the biologic does not retreat up the prongs towards their base during drying or administration.

Obviously, as a single use device, there is no problem of contamination of the biologic with an improperly cleaned applicator, and there is no problem of cleaning or handling of the used instruments.

Among the biologics which may be administered are Old Tuberculin and smallpox vaccine and diagnostic agents for allergens. The above-mentioned patent (2,893,392) discloses some such biologics which may be administered with the present device, including tuberculin tests, tetanus sensitivity, diagnosis of histoplasmosis, blastomycosis, coccidimycosis, cryptococcosis, sporotrichosis, allergen sensitivity, smallpox vaccination, and many other purposes wherein intracutaneous injection of a biological is desired.

Illustrative modifications of the present invention are shown in the accompanying drawings in which:

FIGURE 1 is a plan view of the injector as cut out from sheet metal stock.

FIGURE 2 is a top view after the prongs are bent to position.

FIGURE 3 is a pictorial showing the device ready for use.

FIGURE 4 is a modification using a triangular configuration.

The injector is conveniently formed from noncorrosive metal stock, such as stainless steel or a nickel alloy or aluminum. For stainless steel, the sheets are conveniently 0.006-inch to 0.010-inch thick. .Thinner stock may be used, but the prongs are easily bent. Thicker stock may be used, but the cost is higher, the Wounds are larger, and forming is somewhat more expensive. Larger devices, of course, would be desirable for the administration of biologics to animals which have a tough skin.

The injector itself, as shown in FIGURE 1, is cut from sheet stock as a forming blank 11 which consists of a square plate 12, having a cut-out hole 13, and a plurality of points 14. The hole serves a dual purpose of conserving material and permitting the circulation of liquid around the injector when used with liquid biologics. The prongs 16 are cut externally to the square plate with two prongs adjacent each corner. Conveniently, these prongs are triangular, one side being an extension of the side of the square with an angular cut back to the adjacent side of the square so that, in effect, a right angle triangle is formed, one side of which is integral with the square, along a bend line 15. Preferably, the apex of the prong has an angle of from about 5 to 45, an angle of from 10 to 25 usually gives preferred results. Two prongs 16 adjacent each corner are then bent at right angles to the square plate and into juxtaposition with each other. There is a narrow gap 17 between these adjacent prongs. This gap serves to hold a liquid by capillary action. The adjacent prongs may touch each other at some points. Usually, there is sufiicient spring in the metal so that in the forming operation the prongs are bent into contact, but spring slightly away.

The present device may be formed by a multiple punching operation in which the center hole is first punched from a strip of metal, then an octagonal cut-out forming the interval between two sets of prongs on adjacent injectors, and then the diagonal side of the first pairs of prongs and the straight side of the end prongs, then at the next step the angle side of the second pairs of prongs may be cut leaving a residual narrow neck of metal to keep the injector in the strip, after which a single bending operation bends all eight prongs and completes the cut-out giving the final injector. Such die-forming operations are known to those in the metal-forming trades.

It is preferred that the prongs be from 1 to 10 millimeters in length, with prongs of from 2 to 5 millimeters being preferred. The square plate may conveniently be from about 4-inch to %-inch square; i -inch square gives a convenient size. The gap conveniently has a width of a few thousandths of an inch.

In FIGURE 4 is shown an embodiment having a triangular plate with a total of six prongs bent into three sets of two. Otherwise, the device is essentially the same as shown in the modification of FIGURES l to 3.

In use, the points 14, which preferably lie in the same plane, may be dipped in the biologic which adheres to the points, forming globules 18. If the biologic is to be dried for storage before use, these globules can be dried and remain at the points.

The angular configuration of the points cuts an angular wound which apparently gives greater efficacy than the wound caused by single points.

Having described certain embodiments thereof as our invention, we claim:

1. A one-piece intracutaneous injector comprising:' a substantially flat square plate of corrosion-resistant metal, and adjacent to each of the four corners thereof, and integral therewith, a pair of prongs, one side of each prong being a substantial elongation of one side of the square plate before being bent, said pairs of prongs being bent at approximately a right angle to said square plate and closely adjacent to each other, whereby a liquid, by capillarity, when placed'on said prongs is drawn intothe gap between said prongs.

2. A one-piece intracutaneous injector comprising: a corrosion-resistant metal plate having a flat portion which is triangular in shape, and adjacent to each of the three corners of the triangle, a pair of prongs, the prongs of said pair being respectively integral with the sides of the flat portion meeting at said corner, each prong of saidpairs of prongs being bent at approximately a right angle to the triangular portion and closely adjacent to the other prong of the pair, whereby'a liquid by capillarity when placed on said prongs is drawn into the gap between said prongs; each prong being bent along a side of the triangle and each prong, when flattened to the plane of the triangularportion forming a prong extending in a direction 4 generally at right angles to an edge of said triangular portion.

3. A one-piece intracutaneous injector comprising: a corrosion-resistant metal plate having a flat portion which is a polygon in shape, and has a maximum of four sides, and adjacent to each of the corners of the polygon, a pair of prongs, the prongs of said pair being respectively integral with the sides of the flat portion meeting at said corner, each prong of said pairs of prongs being bent at approximately a right angle to the flat portion and closely adjacent to the other prong of the pair, whereby a liquid by capillarity when placed on said prongs is drawn into the gap between said prongs; each prong being bent along a side of the fiat polygon portion and each prong, when flattened tothe plane of the flat polygon portion, forming a prong having an apex angle of from about 10-25 and extending in a direction generally at right angles to an edge of said flat polygon portion.

"References Cited in the file'of this patent 

1. A ONE-PIECE INTRACUTANEOUS INJECTOR COMPRISING: A SUBSTANTIALLY FLAT SQUARE PLATE OF CORROSION-RESISTANT METAL, AND ADJACENT TO EACH OF THE FOUR CORNERS THEREOF, AND INTEGRAL THEREWITH, A PAIR OF PRONGS, ONE SIDE OF EACH PRONG BEING A SUBSTANTIAL ELONGATION OF ONE SIDE OF THE SQUARE PLATE BEFORE BEING BENT, SAID PAIRS OF PRONGS BEING BENT AT APPROXIMATELY A RIGHT ANGLE TO SAID SQUARE PLATE AND CLOSELY ADJACENT TO EACH OTHER, WHEREBY A LIQUID, BY CAPILLARITY, WHEN PLACED ON SAID PRONGS IS DRAWN INTO THE GAP BETWEEN SAID PRONGS. 